[PATCH] radix-tree: small
Reduce radix tree node memory usage by about a factor of 4 for small files
(< 64K). There are pointer traversal and memory usage costs for large
files with dense pagecache.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 35a2d93..7cbdada 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -33,7 +33,7 @@
#ifdef __KERNEL__
-#define RADIX_TREE_MAP_SHIFT 6
+#define RADIX_TREE_MAP_SHIFT (CONFIG_BASE_SMALL ? 4 : 6)
#else
#define RADIX_TREE_MAP_SHIFT 3 /* For more stressful testing */
#endif